entubar un canal

I'm trying to understand what exactly "entubar un canal" means in English. There's a canal that is very poorly maintained. More and more water flows through it every year, raising the banks, and the government just piles more and more dirt along the banks, so that the canal's water level is actually higher than the land around it. The people who live near the canal are demanding that the government "entubar el canal." What does that mean, exactly?

They want the stream routed through culverts/underground pipes, they want the creek enclosed and routed underground ...
Apparently "culverted" is used in the UK. I haven't seen it here, but it would be understood.

so 'entubar' would be 'to pipe'... I thought this term referred exclusively to domestic dimensions (the piping of a 'canal entubado' might have about 2m diameters). It is good to know it has a wider scope! thanks very much!!!